The field of the present invention relates generally to optical fiber connectors, for connecting together optical fibers of optical fiber cables to one another, and to various devices, and more particularly relates to fiber arrays for holding or retaining optical fibers in V-groove formed in a semiconductor substrate.
It is known in the prior art to provide a fiber array for holding optical fibers within a semiconductor substrate that has V-groove formed in a portion thereof for retaining optical fibers in very precise alignment relative to the longitudinal axis of the substrate.
FIG. 1 shows a typical semiconductor substrate 1, having a plurality of V-groove 3 formed in one portion thereof for retaining uncoated optical fibers (not shown). The fibers are sometimes mechanically secured within the grooves by means not shown, or secured in the grooves 3 through use of an appropriate adhesive. The substrate 1 shown in FIG. 1 also includes a recessed portion 5, in this example, that may be used for receiving a buffer coating for the associated optical fibers. The substrate 1 typically consists of silicon. A problem in the prior art is that a fiber array chip 7, configured as shown in FIG. 1, and consisting of silicon is very expensive. Accordingly, in order to reduce the cost of such a fiber array chip 7, it is desirable to reduce to the greatest extent possible the amount of silicon material that must be used.
In one embodiment of the invention, a relatively small substrate of silicon material has a plurality of V-groove formed across its top face for providing the necessary retention of optical fibers therein for a typical fiber array. The V-groove silicon chip is then secured within an open channel or slotway of a plastic or ceramic mount, that is molded or otherwise formed to provide other necessary mechanical aspects of the fiber array, such as a recessed area adjacent the silicon chip for receiving a buffer coating for the optical fibers, as previously described. Any other required mechanical features can be readily formed in the mount. The V-groove silicon chip can either be secured within the channel of a previously molded mount, or the chip can be placed into mold, for permitting the mount to be molded about the silicon chip during formation of the mount. When the silicon chip is inserted into the channel of the mount after the mount is formed, an appropriate adhesive can be used for rigidly securing the two together. The silicon V-groove chip provides precisely dimensioned and aligned V-groove that cannot otherwise be provided by molding of plastic or ceramic materials, for example. The molded mount provides mechanical features that do not require accurate mechanical sizing, location, and alignment, thereby eliminating the need for using silicon material to provide such other features.
In another embodiment of the invention, the silicon V-groove chip, and molded mount, are formed to provide for joining or interlocking the two together through means of dovetails.
In a third embodiment of the invention, two molded mounts each with a silicon V-groove chip retained therein are sandwiched together with respective V-groove opposing one another for retaining optical fibers therebetween.
In a fourth embodiment of the invention, the molded mounts are provided with means for interlocking the pair of molded mounts with silicon V-groove chips, respectively, in a sandwiched configuration that is securely locked together.
In other embodiments of the invention, the dovetailed interlocking between the V-groove silicon chip and an associated molded mount can include interior corners having non-acute angles. Also, the pair of molded mounts sandwiched together with their respective silicon V-groove chips may include relief pockets in one of the mounts opposing ultrasonic energy directors in the other molded mount to which it is to be mounted, for permitting ultrasonic welding to be used for holding the two together in the sandwiched configuration.
In another embodiment, the silicon V-groove chip may include a transverse trench or slotway in a bottom face, with the top face containing the V-groove, whereby the slotway is filled with the same material used to provide the molded mount, for substantially reducing sliding of the silicon chip within the molded mount.
In yet another embodiment of the invention, a front face of the molded mount is provided with vertically oriented grooves for controlling the wicking of glue, and to also provide a surface area for enhancing the bonding of the glue.
In another embodiment of the invention, the V-groove chip is mounted to extend from the molded mount a sufficient amount to permit reliable and optimal contact between the endfaces of optical fibers to be butt-coupled with the endfaces of optical fibers of an opposing array, for example, with the optical fibers each being retained in an associated V-groove.
In another embodiment of the invention, a strain relief is formed to extend from the rear portion adjacent the recessed area of the molded mount. The strain relief provides for reducing strain upon the optical fibers retained in the associated V-groove of the silicon chip.
In another embodiment of the invention, a notch is formed on a top portion of the molded mount extending from the recessed area thereof, for receiving strengthening fibers typically used in optical fiber cables, to enhance the bonding between an associated optical fiber cable and the molded mount.